On this day, one of the most well known and beloved children’s toys was put into production, the Etch A Sketch.

Designed by French inventor, André Cassagnes, the product went on to sell over 100 million units and has appeared in various incarnations since such as the Etch A Sketch Animator 2000 and the Etch A Sketch Color. It is also frequently named on various top toys lists.

But how does it work?

Well, inside its screen are small bits of aluminium powder. This powder is scraped on and off by the a horizontal and a vertical stylus creating the shapes and pictures we know and love. Shaking the Etch A Sketch puts the powder back inyo place and erases the picture.